1. Field of the Invention
The present invention relates to an array substrate and a reflective-transmissive type liquid crystal display (LCD) apparatus having the array substrate, and more particularly to an array substrate capable of removing an afterimage and enhancing a contrast ratio and a reflective-transmissive type LCD apparatus having the array substrate.
2. Description of the Related Art
In general, a reflective-transmissive type LCD apparatus employing liquid crystal of a mixed twisted nematic (MTN) mode has advantages, for example, such as a high contrast ratio, a high productivity, a high color quality and so on. However, since the reflective-transmissive type LCD apparatus has the liquid crystal twisted, a light transmittance may be deteriorated while the reflective-transmissive type LCD apparatus is operated in a transmissive mode. The liquid crystal of the MTN mode is, generally, twisted in an angle smaller than 90 degrees.
In recent, in order to prevent deterioration of the light transmittance of the MTN mode liquid crystal, a homogeneous mode liquid crystal that the liquid crystal is not twisted is widely used.
In case that the liquid crystal is aligned in the homogenous mode, a cell gap corresponding to a first area and a cell gap corresponding to a second area are different from each other. Especially, when a value of Δnd corresponding to the first area is 0.13 μm and a value of Δnd corresponding to the second area is 0.26 μm, the cell gap corresponding to the second area is twice larger than the cell gap corresponding to the first area. If the liquid crystal has an anisotropic refractive index (Δn) of 0.078, the cell gap corresponding to the first area is 1.7 μm and the cell gap corresponding to the second area is 3.3 μm.
The cell gap corresponding to the first area may be different from the cell gap corresponding to the second area due to an organic insulating layer formed on an array substrate. A disclination, however, may occur at a boundary area between the first area and the second area, and the light may be leaked due to a distorted alignment of the liquid crystal. As a result, an afterimage may appear on a display screen, and a contrast ratio may be lowered.